large darkroom trays

I was wondering if anyone could lead me towards a supplier of supersize printing trays, 30x40 , 40x60 and 48x96 inches or above. I do not want to make them out of wood for a few reasons, but they must be robust enough to handle some serious agitation. As well as the obvious set up and tear down abuse they would receive.
thanks
Bob

You can use those large plastic cement mixing trays found at Home Depot. They are fairly robust and inexpensive (compared to photographic trays). They come in many sizes and stack inside themselves for storage.

You can use those large plastic cement mixing trays found at Home Depot. They are fairly robust and inexpensive (compared to photographic trays). They come in many sizes and stack inside themselves for storage.

Another alternative is the plastic trays that you can get at Home Depot that fit under washing machines.